Document Detail


Absorption of tetraethylammonium (TEA+) by perfused lobster intestine.
MedLine Citation:
PMID:  17397071     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The organic cation, tetraethylammonium (TEA(+)), is actively secreted by mammalian nephrons and crustacean urinary bladders by similar processes in both animal groups. These mechanisms consist of a basolateral Organic Cation Transporter (OCT family) that employs the transmembrane electrical potential as a driving force for organic cation uptake from the blood and a brush border secondary active transport process that exchanges luminal protons for TEA(+). The present study examined the nature of (14)C-TEA(+) transport across the perfused intestinal epithelium of the American lobster, Homarus americanus, to ascertain whether the gut complemented the kidneys in the clearance of these organic metabolites from the blood. Unidirectional mucosa to serosa (M to S) (14)C-TEA(+) fluxes in anterior and posterior intestine were hyperbolic functions of luminal [TEA(+)] and significantly (P<0.01) exceeded the respective serosa to mucosa (S to M) fluxes. Luminal quinine (1 mM) significantly (P<0.05) inhibited M to S flux of the organic cation, while serosal addition of the drug had no effect on S to M transfer of TEA(+). Reducing serosal pH from 7.20 to 6.02 significantly (P<0.01) stimulated M to S transfer of 0.1 mM (14)C-TEA(+), but significantly (P<0.05) lowered S to M transfer of the metabolite. Addition of 2.0 mM unlabelled serosal TEA(+) trans-stimulated the M to S flux of 0.1 mM (14)C-TEA and doubled the transfer rate of the organic cation from lumen to blood compared to its transport in the absence of TEA(+) in the bath. Results suggest that this organic cation is absorbed across lobster intestine by the combination of a brush border OCT-1-like transporter coupled with a basolateral H(+)/TEA(+) exchanger. A working model is presented for intestinal organic cation absorption in crustaceans and compared to the secretory transport model for this class of metabolites previously reported for crustacean and mammalian kidneys.
Authors:
Megan C Piersol; Kenneth M Sterling; Gregory A Ahearn
Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, Non-P.H.S.    
Journal Detail:
Title:  Journal of experimental zoology. Part A, Ecological genetics and physiology     Volume:  307     ISSN:  1932-5223     ISO Abbreviation:  J Exp Zool A Ecol Genet Physiol     Publication Date:  2007 Mar 
Date Detail:
Created Date:  2007-04-02     Completed Date:  2007-04-26     Revised Date:  2009-11-03    
Medline Journal Info:
Nlm Unique ID:  101297745     Medline TA:  J Exp Zool A Ecol Genet Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  176-86     Citation Subset:  IM    
Copyright Information:
(c) 2007 Wiley-Liss, Inc.
Affiliation:
Department of Biology, University of North Florida, Jacksonville, Florida 32224, USA.
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MeSH Terms
Descriptor/Qualifier:
Absorption
Animals
Biological Transport / drug effects
Cations / metabolism
Hydrogen-Ion Concentration
Intestines / metabolism
Mucous Membrane / metabolism
Nephropidae / anatomy & histology,  metabolism*
Organic Cation Transport Proteins / physiology
Quinine / pharmacology
Serous Membrane / metabolism
Tetraethylammonium / metabolism*
Chemical
Reg. No./Substance:
0/Cations; 0/Organic Cation Transport Proteins; 130-95-0/Quinine; 66-40-0/Tetraethylammonium

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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